With the 13th overall selection in the annual First-Year Player Draft, Oakland nabbed University of Southern California junior Grant Green, who's been compared to Rockies shortstop Troy Tulowitzki and Rays third baseman Evan Longoria.

"I'm not in the scouting department, but I know people who have seen him play," A's manager Bob Geren said of Green. "I know our front office is excited, and so am I. He's a big, physical shortstop with athletic ability. That's what you want."

According to MLB.com's scouting reports, Green, a 6-foot-3, 180-pounder who bats from the right side, has five-tool potential at a premium position. He's capable of hitting for average and a little power while playing a fine shortstop.

Green, 21, was advised before the Draft by agent Scott Boras, with whom the A's have been reluctant to deal in the past, in part because Boras' clients have often been difficult to sign.

Green said he hasn't talked numbers with Boras, who also represents Oakland free-agent-to-be Matt Holliday, or the A's.

"I really haven't thought about the whole business side," Green said on a conference call with the Bay Area media on Tuesday night. "Right now, I'm just focused on celebrating the day's accomplishment with my family.

"Let's just take tomorrow when it comes."

A's scouting director Eric Kubota didn't seem overly concerned with the club's ability to sign Green before the Aug. 17 deadline. If Green isn't signed by then, he'll go back into the Draft pool for 2010.

"The bottom line is we think Grant is ready to get his professional career underway," Kubota said, "and we're ready to try to find a way to make that happen."

With five of the top 13 players on their Draft board still available, the A's took a shortstop in the first round for the third time in nine years, and for the second time in five years.

Oakland selected Cliff Pennington of Texas A&M with the 21st overall pick in 2005, and while Pennington made his big league debut late last season, several scouts project him as a second baseman or utility man at the Major League level.

In 2001, the A's used their first-round pick to select shortstop Bobby Crosby out of Long Beach State. Crosby went on to be named the 2004 American League Rookie of the Year, but thereafter he was beset with injuries, and he has since been turned into a utility player.

A free agent at the end of the season, Crosby is unlikely to return. His replacement at shortstop, Orlando Cabrera, also will be a free agent at the end of the year. Given Eric Chavez's injury history, Oakland's future at third base is cloudy as well.

Green said he hasn't been "in tune" with the A's needs, which are fairly obvious: They need long-term help on the left side of the infield. Their shiny new Draft pick, who wouldn't speculate on how long it might take him to make it to the Majors, would prefer to help fill the void at shortstop.

"I know I can stay there," Green said. "It's just a matter of letting the game come to me and not trying to do too much."

Kubota waved off any notion of moving Green.

"He's athletic and he played shortstop at USC for three years," Kubota said. "We generally look at what guys can do, and our general feeling is that this guy can play shortstop.

"I think we always try to look at the Draft as a vacuum and try not to take organizational needs into too much account, but we do think we filled a need, and he was probably the top college middle infielder in the Draft.

The star-crossed career of Crosby obviously didn't dissuade the A's from again looking downstate for a shortstop. Green was born in Anaheim Hills, Calif., and attended La Costa Canyon High School in Carlsbad, Calif.

Selected in the 14th round of the 2006 Draft by the Padres, Green instead opted for college and was a star right away at USC, earning Freshman All-American honors in 2007. His best year with the Trojans came in 2008, when he batted .390 with nine homers, 46 RBIs and 10 stolen bases in 56 games.

After shaking off a slow start to the 2009 campaign, Green batted .374 with a .435 on-base percentage -- tops on the team in both categories -- and hit four homers with 32 RBIs in 54 games to earn All-Pac 10 honors for the second consecutive season.

Said to have excellent range and a strong, accurate arm, Green struggled defensively in the prestigious wood-bat Cape Cod League last summer, making 17 errors in 41 games. That performance, along with his 18 errors and .929 fielding percentage for the Trojans this season, has prompted talk that he might be better suited for third base down the road.

"I'm sure a lot of that came from beginning of this season instead of how I ended up," Green explained, adding that he didn't deal very well with the hype that followed him into his junior season.

"At the very beginning I did terrible with it, and I suffered," he said. "I wasn't trusting my teammates or myself. Once I started trusting, my [defensive] play started going up and up, and I started hitting the way I can. From that, I kind of learned how to have that pressure on me.

"I know that even if I make an error, it's not the end of the world."

Green didn't struggle at all at the plate in the Cape League, batting .348 with six homers, 21 RBIs, 10 stolen bases in 13 attempts and a .451 OBP in 161 at-bats against some of the top pitching prospects in the nation.

At 12th overall last season, Oakland selected second baseman Jemile Weeks out of the University of Miami. After admitting that he didn't know a ton about the A's organization, Green mentioned only Weeks -- and Mark McGwire -- by name.

"I'm just stoked and relieved to be with a great, tradition-rich organization," he said.

Asked to assess his strengths as a player, Green sounded a lot like Crosby did on Draft Day 2001, emphasizing his work ethic over any "wow" factor associated with being a first-rounder.

"I consider myself a baseball player first," Green said. "I'm not gonna be one of those prima donna-type players I'm going to go out play hard, get dirty and play the game the way it's supposed to be played."

The A's didn't have a second-round selection this year, having surrendered it to the White Sox as compensation for signing Cabrera as a Type B free agent. Nor did the A's have a pick in either of Tuesday's compensation rounds, leaving them with plenty of time to kill before making their only other selection of the day.

Round 3, Justin Marks, LHP, University of Louisville: Marks, 21, was the Big East Conference Freshman of the Year in 2007 and a First-Team All-Big East selection in 2008 before going 11-3 with a 3.77 ERA this season while helping the Cardinal to the conference title and a spot in the NCAA Super Regionals. Marks, who is 6-foot-3, 195 pounds and earned the nickname "Big-Game Justin" at Louisville, struck out 129 with 35 walks over 105 innings this year, but he picked a bad time to have one of his worst outings of the season. A 37th-round pick of the Red Sox in the 2006 Draft, Marks gave up six runs on seven hits over 4 1/3 innings of the Cardinals' elimination game against Cal-State Fullerton on Saturday. It was his first loss since March 27.

Mychael Urban is a national writer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.